Kennedy Mensah Osei, Heekang Choi, David Eklu Zeyeh, Salifu Alikamatu, Esther Owusu Boateng, Vandarith Nov, Le Phuong Nguyen, Khadija Kubura, Bernard Bobzah, Dongeun Yong
Ann Clin Microbiol 2022 March, 25(1):1-10. Published on 20 March 2022.
Background: A variety of clinically important pathogens have developed multidrug resistance (MDR), which threatens global public health. This study aimed to determine the incidence, patterns, and trends of MDR of gram-negative bacterial isolates in clinical specimens in the Tamale Teaching Hospital, Ghana.
Methods: This retrospective study analyzed gram-negative bacterial isolates and antimicrobial susceptibility test (AST) results of patients who visited the Tamale Teaching Hospital laboratory between 2017 and 2019.
Results: A total of 2,779 gram-negative bacterial isolates and their phenotypic AST results were analyzed. From these, 1,297 gram-negative bacteria (46.7%) were isolated from urine samples, while the rest were isolated from sputum (20.9%), wound (14.3%), and swabs (11.7%) samples, etc. Escherichia coli (23.8%) was the most common gram-negative pathogen found predominantly in the urine samples (33.2%). All gram-negative bacteria isolated between 2017 and 2019 showed high MDR. Klebsiella pneumoniae gradually increased its MDR from 84.0% in 2017, 89.5% in 2018, to 95.1% in 2019. On the other hand, the MDR rates in Pseudomonas aeruginosa were approximately 65.8%, varying from 59.5% in 2017 to 78.7% in 2019. Among tested antimicrobials, amikacin was the most effective. Resistance to amikacin in Enterobacter spp., E. coli, and K. pneumoniae in vitro were 16.2%, 11.8%, and 17.7%, respectively.
Conclusion: The study has shown that the high levels of MDR in gram-negative bacteria isolated may be associated with the infections recorded at the Tamale Teaching Hospital. The major gram-negative pathogens isolated have resistance to penicillins, cephalosporins, and fluoroquinolones. Aminoglycosides can offer high antibiotic activity to overcome gram-negative bacterial resistance. Further studies will be needed to decide policy direction on infection prevention and control, and antimicrobial stewardship programs.
Jaewoong Lee, Hyunjung Kim, Yang Ree Kim, Haekyung Lee
Ann Clin Microbiol 2022 March, 25(1):11-16. Published on 20 March 2022.
Background: Plasmodium vivax is a major pathogen that causes malaria in Korea. Several genetic polymorphisms in dihydrofolate reductase (pvdhfr), P. vivax multidrug resistance protein 1 (pvmdr1), and P. vivax hydroxymethylpterin pyrophosphokinase-dihydropteroate synthetase (pvdhps) genes are known to be associated with drug resistance in P. vivax. The objective of this study was to profile the known polymorphisms of P. vivax resistance genes in patients at a secondary hospital in Korea.
Methods: A total of 12 patients with confirmed P. vivax infections were enrolled for this study. Sanger sequencing was performed for the pvdhfr, pvmdr1, and pvdhps genes to detect polymorphisms of these drug resistance genes.
Results: Each specimen had single or double polymorphism in pvdhfr. One specimen had a polymorphism in pvdhps. However, no specimen had any polymorphisms in pvmdr1. There was no strain with multi-polymorphisms exceeding double polymorphisms, which reported the geographic location of treatment failure.
Conclusion: No specimen showed chloroquine-resistance polymorphism in pvmdr1. Treatment with first-line therapy was successful. The prevalence of F57L in pvdhfr was higher than that reported previously. This change must be confirmed by further monitoring and surveillance of the strains with multi-polymorphisms.
Young Ah Kim, Heejung Kim, Dokyun Kim, Changseung Liu, Seok Hoon Jeong
Ann Clin Microbiol 2022 March, 25(1):17-23. Published on 20 March 2022.
Background: There has been a marked increase in the mortality rate associated with Clostridioides difficile infection (CDI) globally since 2003, with the emergence of binary toxin-producing ribotype 027 strains. However, the molecular epidemiology of C. difficile shows regional differences and ribotype 027 is not common in Korea. In this study, the risk factors for severe CDI were evaluated, while considering the region-specific molecular epidemiology.
Methods: A retrospective case-control study was performed. Cases (n = 149) included patients with severe CDI or severe complicated CDI. Controls (n = 155) consisted of patients with nonsevere CDI.
Results: Advanced age (odds ratio [OR] = 1.017, P = 0.0358), a history of chemotherapy (OR = 2.695, P = 0.0464), and ribotype 002 (OR = 3.406, P = 0.0231) were statistically significant factors associated with severe CDI in a multivariate analysis.
Conclusion: Ribotype 002 was found to be a significant risk factor for severe CDI in this study. Therefore, the surveillance of C. difficile ribotypes is recommended to monitor the spread of high-risk clones.
Min-Ju Ahn, Dae Gwin Jeong, Kyu-Sun Lee, Seungjun Lee, Byung-Han Ryu, Hye Ryun Yang, Sunjoo Kim
Ann Clin Microbiol 2022 March, 25(1):25-29. Published on 20 March 2022.
Neutralizing antibodies play a critical role in blocking viral infections and in viral clearance during acute infection. The microneutralization assay and enzyme-linked immunosorbent assay (ELISA) targeting the receptor binding domain were performed for 30 patients with mild coronavirus disease (COVID)-19 infections. The elapsed number of days between sample collection and diagnosis was 115 days, and real-time polymerase chain reaction (PCR) cycle threshold (Ct) values at diagnosis were recorded. Clinical characteristics and Ct values were compared between neutralization antibody-positive and -negative patients as measured by the microneutralization assay. Neutralization antibody-positive patients (n = 9) were likely to be older, have low Ct values, have more pneumonia during admission, and have a higher optical density in ELISA than the neutralization antibody-negative patients (n = 21). Elderly people seemed to have a higher viral load causing more pneumonia and to produce more neutralization antibodies. Neutralization antibodies persisted in only 30% of patients as detected by microneutralization test after 100 days of diagnosis.
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